Aluminum-beryllium alloy



Patented Mar. 3, 1942 ALUMINUM-BERYLLIUM ALLOY Carlo Adamoli, Milan, Italy, assignor to Perosa Corporation, Wilmington, Del., a corporation of Delaware No Drawing. Application April 1, 1940, Serial No. 327,245. In Italy June 30, 1937 Claims.

The present application relates to a method for improving aluminium-beryllium alloys and is a continuation-in-part of my prior application Serial No. 172,871 filed on November 5, 1937.

The invention is based on a study of the ternary alloys comprising beryllium alloyed with a basis metal and with another metallic substance added in small proportions, which led to the discovery that if with a basis metal which crystallises in a certain system, a certain proportion of a metallic substance crystallising in a system of the same order, and beryllium are alloyed, it is possible to obtain finally an alloy of the basis metal, beryllium and the additional metallic substance, possessing a very marked homogeneity and remarkable physical properties affording the possibility of industrial application, particularly when the alloy has been subjected to certain physical treatments.

Thus I have discovered that if certain additional metals are introduced into aluminiumberyllium alloys in small proportions comprised between a certain minimum starting from which the additional metal induces a rapid and practically complete solubilisation of beryllium and the reciprocal interpenetration of the aluminium and beryllium, and a certain maximum above which the additional metal would have a prejudicial effect, alloys are obtained which are very homogeneous and possess particular properties such as great hardness, with a high resistance to breaking and a remarkable tenacity, as Well as an electrical conductivity high in comparison with that of known binary aluminium-beryllium alloys.

The process according to the invention consists in introducing into aluminium beryllium alloys containing 1 to 3% of .beryllium, manganese from a trace up to 2%, the balance being substantially all aluminium, and in subjecting the alloys so constituted to the usual treatments of quenching and reprecipitation of the hardening constituent. I

For example the alloys may be quenched in water or in an air blast after heating at a temperature of about 470-515" C., then annealed at a temperature of about 160 to 190 C. for one to ten hours, this treatment then being repeated, if desired.

It appears that the additional metallic substance plays the part of a diffusing, homogenising or solubilising agent for the beryllium or for the definite compounds which may be formed. It would appear notably that the geometrical crystalline structure corresponds, in certain alloys,

particularly when they have been subjected to such treatments as indicated above, to the geometrical crystalline structure of the basis metal.

The alloys according to the invention afiord a considerable technical progress in the manufacture of springs, needles and all other objects or articles which necessitate notably maximum elasticity even under very high mechanical stress with a great hardness and also a greatly reduced oxidisability and a considerable facility for manufacture without appreciable oxidation.

Notably, alloys are obtained which possess a very high mechanical resistance whether in the cast or machined state. These alloys possess a very great hardness, and resistance to wear, and can thus be used, among other things, for ball or roller bearings, bearings generally, springs, for example laminated springs, and the like.

The alloys according to the invention possess extremely good mechanical and electrical properties and take a good temper after heating at a temperature considerably lower than that required for the usual alloys of beryllium, which has the advantage of lessening and practically removing the risk of approaching the fusion temperature or the disintegration of the alloy.

Apart from the basis metal, beryllium and the metal solubilising agent, the alloys may contain in addition various elements in very small proportions; in particular, iron can be added in a proportion in any case less than 4%, in order to give the alloy a very high fluidity in casting. It is only in the case of conducting alloys that it is preferable to refrain from adding iron.

What I claim is:

l. A process for improving the physicomechanical properties of alloys of beryllium with aluminium consisting in introducing into aluminium-beryllium alloys containing beryllium in a proportion of about 1 to 3%, manganese in a proportion from a trace up to 2%, the balance being substantially all aluminium, heating the alloys so constituted at a temperature of about 470 to 515 C., then cooling the same rapidly and subjecting them to an annealing treatment producing the reprecipitation of the hardening constituent diffused in the alloys.

2. A process for improving the physicomechanical properties of alloys of beryllium with aluminium consisting in introducing into aluminium-beryllium alloys containing beryllium in a proportion of about 1 to 3%, manganese in a proportion from a trace up to 2%, the balance being substantially all aluminium, heating the alloys so constituted at a temperature of about 470 to 515 C., then cooling the same rapidly and subjecting them to an annealing treatment at a temperature of about 160 to 190 C. for one to ten hours.

3. An aluminium-beryllium alloy containing beryllium in a proportion of about 1 to 3% and as a metallic substance acting as a difiusing, solubilizing and homogenizing agent for beryllium, manganese in a proportion from a trace up to 2%, the balance being substantially all aluminium.

4. An aluminium-beryllium alloy containing beryllium in a proportion of about 1 to 3% and as a metallic substance acting as a diffusing, solubilizing and homogenizing agent for beryllium, manganese in a proportion from a trace up to 2%, the balance being substantially all aluminium, the said alloy having been hardened by heating the alloy to a temperature of about 470 to 515 C., then cooling the same rapidly and subjecting it to an annealing treatment producing the reprecipitation of the hardening constituent diffused in the alloy.

5. An aluminium-beryllium alloy containing beryllium in a proportion of about 1 to 3% and as a metallic substance acting as a difiusing, solubilizing and homogenizing agent for beryllium, manganese in a proportion from a trace up to 2%, the balance being substantially all aluminium, the said alloy having been hardened by heating the alloy to a temperature of about 470 to 515 C., then cooling the same rapidly and subjecting it to an annealing treatment at a temperature of about 160 to 190 C. for one to ten ours.

CARLO ADAMOLI. 

